The present invention relates to a compressor.
Refrigerant gas that flows in a compressor typically contains lubricant to lubricate sliding parts in the compressor in a favorable manner. However, circulating the refrigerant gas that contains lubricant between an external refrigerant circuit and the compressor reduces the efficiency of a refrigeration cycle. To prevent the refrigerant gas containing lubricant from flowing to the external refrigerant circuit from the compressor, a compressor equipped with an oil separator for separating the lubricant from the refrigerant gas has been disclosed in, for example, Japanese Laid-Open Patent Publication No. 11-82353. The oil separator includes an outer tube located in a discharge chamber, an inner tube arranged in the outer tube, and a hollow portion that is an oil separation chamber formed between the outer tube and the inner tube. The refrigerant gas introduced from the discharge chamber to the hollow portion swirls around the inner tube so that the lubricant is separated from the refrigerant gas.
The compressor of Japanese Laid-Open Patent Publication No. 11-82353 is arranged such that the inner tube extends vertically to improve particularly the separation efficiency of the oil separator. Thus, the refrigerant gas in the discharge chamber needs to be introduced from the upper section of the discharge chamber into the hollow portion. This causes the lubricant separated from the refrigerant gas in the discharge chamber to easily accumulate in the lower part of the discharge chamber. For this reason, in anticipation of accumulation of lubricant in the lower part of the discharge chamber, an extra lubricant of the amount corresponding to the anticipated accumulation needs to be included in the compressor in advance.